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A094091
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a(1) = 0; for n>0, a(n) = smaller of 0 and 1 such that we avoid the property that, for some i and j in the range S = 2 <= i < j <= n/2, a(i) ... a(2i) is a subsequence of a(j) ... a(2j).
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3
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0, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 0, 0
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OFFSET
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1,1
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COMMENTS
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This is a finite sequence of length 23 (necessarily <= A093382(2) = 31).
For S >= 1 define a sequence by a(1) = 0; for n>0, a(n) = smaller of 0 and 1 such that we avoid the property that, for some i and j in the range S <= i < j <= n/2, a(i) ... a(2i) is a subsequence of a(j) ... a(2j). The present sequence is the case S=2. For S=1 we get a sequence of length 3, namely 0,0,0, and A096094, A106197 are the cases S=3 and S=4. A093382(S) gives an upper bound on their lengths.
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LINKS
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EXAMPLE
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After a(1) = a(2) = a(3) = a(4) = 0 we must have a(5) = 1, or else we would have a(2)a(3)a(4) = 000 as a subsequence of a(3)a(4)a(5)a(6) = 000a(6).
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CROSSREFS
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KEYWORD
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nonn,fini,full,easy
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AUTHOR
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EXTENSIONS
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The remaining terms, a(17)-a(23), were sent by Joshua Zucker, Jul 23 2006
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STATUS
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approved
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